Merge branch 'topic/cec' into patchwork

* topic/cec:
  [media] DocBook/media: add CEC documentation
  [media] s5p_cec: get rid of an unused var
  [media] move s5p-cec to staging
  [media] vivid: add CEC emulation
  [media] cec: s5p-cec: Add s5p-cec driver
  [media] cec: adv7511: add cec support
  [media] cec: adv7842: add cec support
  [media] cec: adv7604: add cec support
  [media] cec: add compat32 ioctl support
  [media] cec/TODO: add TODO file so we know why this is still in staging
  [media] cec: add HDMI CEC framework (api)
  [media] cec: add HDMI CEC framework (adapter)
  [media] cec: add HDMI CEC framework (core)
  [media] cec-funcs.h: static inlines to pack/unpack CEC messages
  [media] cec.h: add cec header
  [media] cec-edid: add module for EDID CEC helper functions
  [media] cec.txt: add CEC framework documentation
  [media] rc: Add HDMI CEC protocol handling

17 files changed, 3447 insertions, 0 deletions

diff --git a/drivers/staging/media/Kconfig b/drivers/staging/media/Kconfig
index ee9186843371..567078986c94 100644
--- a/drivers/staging/media/Kconfig
+++ b/drivers/staging/media/Kconfig
@@ -21,6 +21,8 @@ if STAGING_MEDIA
 # Please keep them in alphabetic order
 source "drivers/staging/media/bcm2048/Kconfig"
 
+source "drivers/staging/media/cec/Kconfig"
+
 source "drivers/staging/media/cxd2099/Kconfig"
 
 source "drivers/staging/media/davinci_vpfe/Kconfig"
@@ -29,6 +31,8 @@ source "drivers/staging/media/omap4iss/Kconfig"
 
 source "drivers/staging/media/tw686x-kh/Kconfig"
 
+source "drivers/staging/media/s5p-cec/Kconfig"
+
 # Keep LIRC at the end, as it has sub-menus
 source "drivers/staging/media/lirc/Kconfig"
 
diff --git a/drivers/staging/media/Makefile b/drivers/staging/media/Makefile
index 8c05d0ace0fb..989c844f4996 100644
--- a/drivers/staging/media/Makefile
+++ b/drivers/staging/media/Makefile
@@ -1,4 +1,6 @@
 obj-$(CONFIG_I2C_BCM2048)	+= bcm2048/
+obj-$(CONFIG_MEDIA_CEC)		+= cec/
+obj-$(CONFIG_VIDEO_SAMSUNG_S5P_CEC) += s5p-cec/
 obj-$(CONFIG_DVB_CXD2099)	+= cxd2099/
 obj-$(CONFIG_LIRC_STAGING)	+= lirc/
 obj-$(CONFIG_VIDEO_DM365_VPFE)	+= davinci_vpfe/
diff --git a/drivers/staging/media/cec/Kconfig b/drivers/staging/media/cec/Kconfig
new file mode 100644
index 000000000000..8a7aceeac815
--- /dev/null
+++ b/drivers/staging/media/cec/Kconfig
@@ -0,0 +1,14 @@
+config MEDIA_CEC
+	tristate "CEC API (EXPERIMENTAL)"
+	select MEDIA_CEC_EDID
+	---help---
+	  Enable the CEC API.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cec.
+
+config MEDIA_CEC_DEBUG
+	bool "CEC debugfs interface (EXPERIMENTAL)"
+	depends on MEDIA_CEC && DEBUG_FS
+	---help---
+	  Turns on the DebugFS interface for CEC devices.
diff --git a/drivers/staging/media/cec/Makefile b/drivers/staging/media/cec/Makefile
new file mode 100644
index 000000000000..426ef73b959f
--- /dev/null
+++ b/drivers/staging/media/cec/Makefile
@@ -0,0 +1,3 @@
+cec-objs := cec-core.o cec-adap.o cec-api.o
+
+obj-$(CONFIG_MEDIA_CEC) += cec.o
diff --git a/drivers/staging/media/cec/TODO b/drivers/staging/media/cec/TODO
new file mode 100644
index 000000000000..a8f4b7df38c8
--- /dev/null
+++ b/drivers/staging/media/cec/TODO
@@ -0,0 +1,27 @@
+The reason why cec.c is still in staging is that I would like
+to have a bit more confidence in the uABI. The kABI is fine,
+no problem there, but I would like to let the public API mature
+a bit.
+
+Once I'm confident that I didn't miss anything then the cec.c source
+can move to drivers/media and the linux/cec.h and linux/cec-funcs.h
+headers can move to uapi/linux and added to uapi/linux/Kbuild to make
+them public.
+
+Hopefully this will happen later in 2016.
+
+Other TODOs:
+
+- Add a flag to inhibit passing CEC RC messages to the rc subsystem.
+  Applications should be able to choose this when calling S_LOG_ADDRS.
+- Convert cec.txt to sphinx.
+- If the reply field of cec_msg is set then when the reply arrives it
+  is only sent to the filehandle that transmitted the original message
+  and not to any followers. Should this behavior change or perhaps
+  controlled through a cec_msg flag?
+- Should CEC_LOG_ADDR_TYPE_SPECIFIC be replaced by TYPE_2ND_TV and TYPE_PROCESSOR?
+  And also TYPE_SWITCH and TYPE_CDC_ONLY in addition to the TYPE_UNREGISTERED?
+  This should give the framework more information about the device type
+  since SPECIFIC and UNREGISTERED give no useful information.
+
+Hans Verkuil <hans.verkuil@cisco.com>
diff --git a/drivers/staging/media/cec/cec-adap.c b/drivers/staging/media/cec/cec-adap.c
new file mode 100644
index 000000000000..5ffa839e5dec
--- /dev/null
+++ b/drivers/staging/media/cec/cec-adap.c
@@ -0,0 +1,1627 @@
+/*
+ * cec-adap.c - HDMI Consumer Electronics Control framework - CEC adapter
+ *
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "cec-priv.h"
+
+static int cec_report_features(struct cec_adapter *adap, unsigned int la_idx);
+static int cec_report_phys_addr(struct cec_adapter *adap, unsigned int la_idx);
+
+/*
+ * 400 ms is the time it takes for one 16 byte message to be
+ * transferred and 5 is the maximum number of retries. Add
+ * another 100 ms as a margin. So if the transmit doesn't
+ * finish before that time something is really wrong and we
+ * have to time out.
+ *
+ * This is a sign that something it really wrong and a warning
+ * will be issued.
+ */
+#define CEC_XFER_TIMEOUT_MS (5 * 400 + 100)
+
+#define call_op(adap, op, arg...) \
+	(adap->ops->op ? adap->ops->op(adap, ## arg) : 0)
+
+#define call_void_op(adap, op, arg...)			\
+	do {						\
+		if (adap->ops->op)			\
+			adap->ops->op(adap, ## arg);	\
+	} while (0)
+
+static int cec_log_addr2idx(const struct cec_adapter *adap, u8 log_addr)
+{
+	int i;
+
+	for (i = 0; i < adap->log_addrs.num_log_addrs; i++)
+		if (adap->log_addrs.log_addr[i] == log_addr)
+			return i;
+	return -1;
+}
+
+static unsigned int cec_log_addr2dev(const struct cec_adapter *adap, u8 log_addr)
+{
+	int i = cec_log_addr2idx(adap, log_addr);
+
+	return adap->log_addrs.primary_device_type[i < 0 ? 0 : i];
+}
+
+/*
+ * Queue a new event for this filehandle. If ts == 0, then set it
+ * to the current time.
+ *
+ * The two events that are currently defined do not need to keep track
+ * of intermediate events, so no actual queue of events is needed,
+ * instead just store the latest state and the total number of lost
+ * messages.
+ *
+ * Should new events be added in the future that require intermediate
+ * results to be queued as well, then a proper queue data structure is
+ * required. But until then, just keep it simple.
+ */
+void cec_queue_event_fh(struct cec_fh *fh,
+			const struct cec_event *new_ev, u64 ts)
+{
+	struct cec_event *ev = &fh->events[new_ev->event - 1];
+
+	if (ts == 0)
+		ts = ktime_get_ns();
+
+	mutex_lock(&fh->lock);
+	if (new_ev->event == CEC_EVENT_LOST_MSGS &&
+	    fh->pending_events & (1 << new_ev->event)) {
+		/*
+		 * If there is already a lost_msgs event, then just
+		 * update the lost_msgs count. This effectively
+		 * merges the old and new events into one.
+		 */
+		ev->lost_msgs.lost_msgs += new_ev->lost_msgs.lost_msgs;
+		goto unlock;
+	}
+
+	/*
+	 * Intermediate states are not interesting, so just
+	 * overwrite any older event.
+	 */
+	*ev = *new_ev;
+	ev->ts = ts;
+	fh->pending_events |= 1 << new_ev->event;
+
+unlock:
+	mutex_unlock(&fh->lock);
+	wake_up_interruptible(&fh->wait);
+}
+
+/* Queue a new event for all open filehandles. */
+static void cec_queue_event(struct cec_adapter *adap,
+			    const struct cec_event *ev)
+{
+	u64 ts = ktime_get_ns();
+	struct cec_fh *fh;
+
+	mutex_lock(&adap->devnode.fhs_lock);
+	list_for_each_entry(fh, &adap->devnode.fhs, list)
+		cec_queue_event_fh(fh, ev, ts);
+	mutex_unlock(&adap->devnode.fhs_lock);
+}
+
+/*
+ * Queue a new message for this filehandle. If there is no more room
+ * in the queue, then send the LOST_MSGS event instead.
+ */
+static void cec_queue_msg_fh(struct cec_fh *fh, const struct cec_msg *msg)
+{
+	static const struct cec_event ev_lost_msg = {
+		.event = CEC_EVENT_LOST_MSGS,
+		.lost_msgs.lost_msgs = 1,
+	};
+	struct cec_msg_entry *entry;
+
+	mutex_lock(&fh->lock);
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		goto lost_msgs;
+
+	entry->msg = *msg;
+	/* Add new msg at the end of the queue */
+	list_add_tail(&entry->list, &fh->msgs);
+
+	/*
+	 * if the queue now has more than CEC_MAX_MSG_QUEUE_SZ
+	 * messages, drop the oldest one and send a lost message event.
+	 */
+	if (fh->queued_msgs == CEC_MAX_MSG_QUEUE_SZ) {
+		list_del(&entry->list);
+		goto lost_msgs;
+	}
+	fh->queued_msgs++;
+	mutex_unlock(&fh->lock);
+	wake_up_interruptible(&fh->wait);
+	return;
+
+lost_msgs:
+	mutex_unlock(&fh->lock);
+	cec_queue_event_fh(fh, &ev_lost_msg, 0);
+}
+
+/*
+ * Queue the message for those filehandles that are in monitor mode.
+ * If valid_la is true (this message is for us or was sent by us),
+ * then pass it on to any monitoring filehandle. If this message
+ * isn't for us or from us, then only give it to filehandles that
+ * are in MONITOR_ALL mode.
+ *
+ * This can only happen if the CEC_CAP_MONITOR_ALL capability is
+ * set and the CEC adapter was placed in 'monitor all' mode.
+ */
+static void cec_queue_msg_monitor(struct cec_adapter *adap,
+				  const struct cec_msg *msg,
+				  bool valid_la)
+{
+	struct cec_fh *fh;
+	u32 monitor_mode = valid_la ? CEC_MODE_MONITOR :
+				      CEC_MODE_MONITOR_ALL;
+
+	mutex_lock(&adap->devnode.fhs_lock);
+	list_for_each_entry(fh, &adap->devnode.fhs, list) {
+		if (fh->mode_follower >= monitor_mode)
+			cec_queue_msg_fh(fh, msg);
+	}
+	mutex_unlock(&adap->devnode.fhs_lock);
+}
+
+/*
+ * Queue the message for follower filehandles.
+ */
+static void cec_queue_msg_followers(struct cec_adapter *adap,
+				    const struct cec_msg *msg)
+{
+	struct cec_fh *fh;
+
+	mutex_lock(&adap->devnode.fhs_lock);
+	list_for_each_entry(fh, &adap->devnode.fhs, list) {
+		if (fh->mode_follower == CEC_MODE_FOLLOWER)
+			cec_queue_msg_fh(fh, msg);
+	}
+	mutex_unlock(&adap->devnode.fhs_lock);
+}
+
+/* Notify userspace of an adapter state change. */
+static void cec_post_state_event(struct cec_adapter *adap)
+{
+	struct cec_event ev = {
+		.event = CEC_EVENT_STATE_CHANGE,
+	};
+
+	ev.state_change.phys_addr = adap->phys_addr;
+	ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
+	cec_queue_event(adap, &ev);
+}
+
+/*
+ * A CEC transmit (and a possible wait for reply) completed.
+ * If this was in blocking mode, then complete it, otherwise
+ * queue the message for userspace to dequeue later.
+ *
+ * This function is called with adap->lock held.
+ */
+static void cec_data_completed(struct cec_data *data)
+{
+	/*
+	 * Delete this transmit from the filehandle's xfer_list since
+	 * we're done with it.
+	 *
+	 * Note that if the filehandle is closed before this transmit
+	 * finished, then the release() function will set data->fh to NULL.
+	 * Without that we would be referring to a closed filehandle.
+	 */
+	if (data->fh)
+		list_del(&data->xfer_list);
+
+	if (data->blocking) {
+		/*
+		 * Someone is blocking so mark the message as completed
+		 * and call complete.
+		 */
+		data->completed = true;
+		complete(&data->c);
+	} else {
+		/*
+		 * No blocking, so just queue the message if needed and
+		 * free the memory.
+		 */
+		if (data->fh)
+			cec_queue_msg_fh(data->fh, &data->msg);
+		kfree(data);
+	}
+}
+
+/*
+ * A pending CEC transmit needs to be cancelled, either because the CEC
+ * adapter is disabled or the transmit takes an impossibly long time to
+ * finish.
+ *
+ * This function is called with adap->lock held.
+ */
+static void cec_data_cancel(struct cec_data *data)
+{
+	/*
+	 * It's either the current transmit, or it is a pending
+	 * transmit. Take the appropriate action to clear it.
+	 */
+	if (data->adap->transmitting == data)
+		data->adap->transmitting = NULL;
+	else
+		list_del_init(&data->list);
+
+	/* Mark it as an error */
+	data->msg.ts = ktime_get_ns();
+	data->msg.tx_status = CEC_TX_STATUS_ERROR |
+			      CEC_TX_STATUS_MAX_RETRIES;
+	data->attempts = 0;
+	data->msg.tx_error_cnt = 1;
+	data->msg.reply = 0;
+	/* Queue transmitted message for monitoring purposes */
+	cec_queue_msg_monitor(data->adap, &data->msg, 1);
+
+	cec_data_completed(data);
+}
+
+/*
+ * Main CEC state machine
+ *
+ * Wait until the thread should be stopped, or we are not transmitting and
+ * a new transmit message is queued up, in which case we start transmitting
+ * that message. When the adapter finished transmitting the message it will
+ * call cec_transmit_done().
+ *
+ * If the adapter is disabled, then remove all queued messages instead.
+ *
+ * If the current transmit times out, then cancel that transmit.
+ */
+int cec_thread_func(void *_adap)
+{
+	struct cec_adapter *adap = _adap;
+
+	for (;;) {
+		unsigned int signal_free_time;
+		struct cec_data *data;
+		bool timeout = false;
+		u8 attempts;
+
+		if (adap->transmitting) {
+			int err;
+
+			/*
+			 * We are transmitting a message, so add a timeout
+			 * to prevent the state machine to get stuck waiting
+			 * for this message to finalize and add a check to
+			 * see if the adapter is disabled in which case the
+			 * transmit should be canceled.
+			 */
+			err = wait_event_interruptible_timeout(adap->kthread_waitq,
+				kthread_should_stop() ||
+				adap->phys_addr == CEC_PHYS_ADDR_INVALID ||
+				(!adap->transmitting &&
+				 !list_empty(&adap->transmit_queue)),
+				msecs_to_jiffies(CEC_XFER_TIMEOUT_MS));
+			timeout = err == 0;
+		} else {
+			/* Otherwise we just wait for something to happen. */
+			wait_event_interruptible(adap->kthread_waitq,
+				kthread_should_stop() ||
+				(!adap->transmitting &&
+				 !list_empty(&adap->transmit_queue)));
+		}
+
+		mutex_lock(&adap->lock);
+
+		if (adap->phys_addr == CEC_PHYS_ADDR_INVALID ||
+		    kthread_should_stop()) {
+			/*
+			 * If the adapter is disabled, or we're asked to stop,
+			 * then cancel any pending transmits.
+			 */
+			while (!list_empty(&adap->transmit_queue)) {
+				data = list_first_entry(&adap->transmit_queue,
+							struct cec_data, list);
+				cec_data_cancel(data);
+			}
+			if (adap->transmitting)
+				cec_data_cancel(adap->transmitting);
+
+			/*
+			 * Cancel the pending timeout work. We have to unlock
+			 * the mutex when flushing the work since
+			 * cec_wait_timeout() will take it. This is OK since
+			 * no new entries can be added to wait_queue as long
+			 * as adap->transmitting is NULL, which it is due to
+			 * the cec_data_cancel() above.
+			 */
+			while (!list_empty(&adap->wait_queue)) {
+				data = list_first_entry(&adap->wait_queue,
+							struct cec_data, list);
+
+				if (!cancel_delayed_work(&data->work)) {
+					mutex_unlock(&adap->lock);
+					flush_scheduled_work();
+					mutex_lock(&adap->lock);
+				}
+				cec_data_cancel(data);
+			}
+			goto unlock;
+		}
+
+		if (adap->transmitting && timeout) {
+			/*
+			 * If we timeout, then log that. This really shouldn't
+			 * happen and is an indication of a faulty CEC adapter
+			 * driver, or the CEC bus is in some weird state.
+			 */
+			dprintk(0, "message %*ph timed out!\n",
+				adap->transmitting->msg.len,
+				adap->transmitting->msg.msg);
+			/* Just give up on this. */
+			cec_data_cancel(adap->transmitting);
+			goto unlock;
+		}
+
+		/*
+		 * If we are still transmitting, or there is nothing new to
+		 * transmit, then just continue waiting.
+		 */
+		if (adap->transmitting || list_empty(&adap->transmit_queue))
+			goto unlock;
+
+		/* Get a new message to transmit */
+		data = list_first_entry(&adap->transmit_queue,
+					struct cec_data, list);
+		list_del_init(&data->list);
+		/* Make this the current transmitting message */
+		adap->transmitting = data;
+
+		/*
+		 * Suggested number of attempts as per the CEC 2.0 spec:
+		 * 4 attempts is the default, except for 'secondary poll
+		 * messages', i.e. poll messages not sent during the adapter
+		 * configuration phase when it allocates logical addresses.
+		 */
+		if (data->msg.len == 1 && adap->is_configured)
+			attempts = 2;
+		else
+			attempts = 4;
+
+		/* Set the suggested signal free time */
+		if (data->attempts) {
+			/* should be >= 3 data bit periods for a retry */
+			signal_free_time = CEC_SIGNAL_FREE_TIME_RETRY;
+		} else if (data->new_initiator) {
+			/* should be >= 5 data bit periods for new initiator */
+			signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
+		} else {
+			/*
+			 * should be >= 7 data bit periods for sending another
+			 * frame immediately after another.
+			 */
+			signal_free_time = CEC_SIGNAL_FREE_TIME_NEXT_XFER;
+		}
+		if (data->attempts == 0)
+			data->attempts = attempts;
+
+		/* Tell the adapter to transmit, cancel on error */
+		if (adap->ops->adap_transmit(adap, data->attempts,
+					     signal_free_time, &data->msg))
+			cec_data_cancel(data);
+
+unlock:
+		mutex_unlock(&adap->lock);
+
+		if (kthread_should_stop())
+			break;
+	}
+	return 0;
+}
+
+/*
+ * Called by the CEC adapter if a transmit finished.
+ */
+void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
+		       u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt)
+{
+	struct cec_data *data;
+	struct cec_msg *msg;
+
+	dprintk(2, "cec_transmit_done %02x\n", status);
+	mutex_lock(&adap->lock);
+	data = adap->transmitting;
+	if (!data) {
+		/*
+		 * This can happen if a transmit was issued and the cable is
+		 * unplugged while the transmit is ongoing. Ignore this
+		 * transmit in that case.
+		 */
+		dprintk(1, "cec_transmit_done without an ongoing transmit!\n");
+		goto unlock;
+	}
+
+	msg = &data->msg;
+
+	/* Drivers must fill in the status! */
+	WARN_ON(status == 0);
+	msg->ts = ktime_get_ns();
+	msg->tx_status |= status;
+	msg->tx_arb_lost_cnt += arb_lost_cnt;
+	msg->tx_nack_cnt += nack_cnt;
+	msg->tx_low_drive_cnt += low_drive_cnt;
+	msg->tx_error_cnt += error_cnt;
+
+	/* Mark that we're done with this transmit */
+	adap->transmitting = NULL;
+
+	/*
+	 * If there are still retry attempts left and there was an error and
+	 * the hardware didn't signal that it retried itself (by setting
+	 * CEC_TX_STATUS_MAX_RETRIES), then we will retry ourselves.
+	 */
+	if (data->attempts > 1 &&
+	    !(status & (CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_OK))) {
+		/* Retry this message */
+		data->attempts--;
+		/* Add the message in front of the transmit queue */
+		list_add(&data->list, &adap->transmit_queue);
+		goto wake_thread;
+	}
+
+	data->attempts = 0;
+
+	/* Always set CEC_TX_STATUS_MAX_RETRIES on error */
+	if (!(status & CEC_TX_STATUS_OK))
+		msg->tx_status |= CEC_TX_STATUS_MAX_RETRIES;
+
+	/* Queue transmitted message for monitoring purposes */
+	cec_queue_msg_monitor(adap, msg, 1);
+
+	/*
+	 * Clear reply and timeout on error or if the adapter is no longer
+	 * configured. It makes no sense to wait for a reply in that case.
+	 */
+	if (!(status & CEC_TX_STATUS_OK) || !adap->is_configured) {
+		msg->reply = 0;
+		msg->timeout = 0;
+	}
+
+	if (msg->timeout) {
+		/*
+		 * Queue the message into the wait queue if we want to wait
+		 * for a reply.
+		 */
+		list_add_tail(&data->list, &adap->wait_queue);
+		schedule_delayed_work(&data->work,
+				      msecs_to_jiffies(msg->timeout));
+	} else {
+		/* Otherwise we're done */
+		cec_data_completed(data);
+	}
+
+wake_thread:
+	/*
+	 * Wake up the main thread to see if another message is ready
+	 * for transmitting or to retry the current message.
+	 */
+	wake_up_interruptible(&adap->kthread_waitq);
+unlock:
+	mutex_unlock(&adap->lock);
+}
+EXPORT_SYMBOL_GPL(cec_transmit_done);
+
+/*
+ * Called when waiting for a reply times out.
+ */
+static void cec_wait_timeout(struct work_struct *work)
+{
+	struct cec_data *data = container_of(work, struct cec_data, work.work);
+	struct cec_adapter *adap = data->adap;
+
+	mutex_lock(&adap->lock);
+	/*
+	 * Sanity check in case the timeout and the arrival of the message
+	 * happened at the same time.
+	 */
+	if (list_empty(&data->list))
+		goto unlock;
+
+	/* Mark the message as timed out */
+	list_del_init(&data->list);
+	data->msg.ts = ktime_get_ns();
+	data->msg.rx_status = CEC_RX_STATUS_TIMEOUT;
+	cec_data_completed(data);
+unlock:
+	mutex_unlock(&adap->lock);
+}
+
+/*
+ * Transmit a message. The fh argument may be NULL if the transmit is not
+ * associated with a specific filehandle.
+ *
+ * This function is called with adap->lock held.
+ */
+int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg,
+			struct cec_fh *fh, bool block)
+{
+	struct cec_data *data;
+	u8 last_initiator = 0xff;
+	unsigned int timeout;
+	int res = 0;
+
+	if (msg->reply && msg->timeout == 0) {
+		/* Make sure the timeout isn't 0. */
+		msg->timeout = 1000;
+	}
+
+	/* Sanity checks */
+	if (msg->len == 0 || msg->len > CEC_MAX_MSG_SIZE) {
+		dprintk(1, "cec_transmit_msg: invalid length %d\n", msg->len);
+		return -EINVAL;
+	}
+	if (msg->timeout && msg->len == 1) {
+		dprintk(1, "cec_transmit_msg: can't reply for poll msg\n");
+		return -EINVAL;
+	}
+	if (msg->len == 1) {
+		if (cec_msg_initiator(msg) != 0xf ||
+		    cec_msg_destination(msg) == 0xf) {
+			dprintk(1, "cec_transmit_msg: invalid poll message\n");
+			return -EINVAL;
+		}
+		if (cec_has_log_addr(adap, cec_msg_destination(msg))) {
+			/*
+			 * If the destination is a logical address our adapter
+			 * has already claimed, then just NACK this.
+			 * It depends on the hardware what it will do with a
+			 * POLL to itself (some OK this), so it is just as
+			 * easy to handle it here so the behavior will be
+			 * consistent.
+			 */
+			msg->tx_status = CEC_TX_STATUS_NACK |
+					 CEC_TX_STATUS_MAX_RETRIES;
+			msg->tx_nack_cnt = 1;
+			return 0;
+		}
+	}
+	if (msg->len > 1 && !cec_msg_is_broadcast(msg) &&
+	    cec_has_log_addr(adap, cec_msg_destination(msg))) {
+		dprintk(1, "cec_transmit_msg: destination is the adapter itself\n");
+		return -EINVAL;
+	}
+	if (cec_msg_initiator(msg) != 0xf &&
+	    !cec_has_log_addr(adap, cec_msg_initiator(msg))) {
+		dprintk(1, "cec_transmit_msg: initiator has unknown logical address %d\n",
+			cec_msg_initiator(msg));
+		return -EINVAL;
+	}
+	if (!adap->is_configured && !adap->is_configuring)
+		return -ENONET;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	if (msg->len > 1 && msg->msg[1] == CEC_MSG_CDC_MESSAGE) {
+		msg->msg[2] = adap->phys_addr >> 8;
+		msg->msg[3] = adap->phys_addr & 0xff;
+	}
+
+	if (msg->timeout)
+		dprintk(2, "cec_transmit_msg: %*ph (wait for 0x%02x%s)\n",
+			msg->len, msg->msg, msg->reply, !block ? ", nb" : "");
+	else
+		dprintk(2, "cec_transmit_msg: %*ph%s\n",
+			msg->len, msg->msg, !block ? " (nb)" : "");
+
+	msg->rx_status = 0;
+	msg->tx_status = 0;
+	msg->tx_arb_lost_cnt = 0;
+	msg->tx_nack_cnt = 0;
+	msg->tx_low_drive_cnt = 0;
+	msg->tx_error_cnt = 0;
+	data->msg = *msg;
+	data->fh = fh;
+	data->adap = adap;
+	data->blocking = block;
+
+	/*
+	 * Determine if this message follows a message from the same
+	 * initiator. Needed to determine the free signal time later on.
+	 */
+	if (msg->len > 1) {
+		if (!(list_empty(&adap->transmit_queue))) {
+			const struct cec_data *last;
+
+			last = list_last_entry(&adap->transmit_queue,
+					       const struct cec_data, list);
+			last_initiator = cec_msg_initiator(&last->msg);
+		} else if (adap->transmitting) {
+			last_initiator =
+				cec_msg_initiator(&adap->transmitting->msg);
+		}
+	}
+	data->new_initiator = last_initiator != cec_msg_initiator(msg);
+	init_completion(&data->c);
+	INIT_DELAYED_WORK(&data->work, cec_wait_timeout);
+
+	data->msg.sequence = adap->sequence++;
+	if (fh)
+		list_add_tail(&data->xfer_list, &fh->xfer_list);
+	list_add_tail(&data->list, &adap->transmit_queue);
+	if (!adap->transmitting)
+		wake_up_interruptible(&adap->kthread_waitq);
+
+	/* All done if we don't need to block waiting for completion */
+	if (!block)
+		return 0;
+
+	/*
+	 * If we don't get a completion before this time something is really
+	 * wrong and we time out.
+	 */
+	timeout = CEC_XFER_TIMEOUT_MS;
+	/* Add the requested timeout if we have to wait for a reply as well */
+	if (msg->timeout)
+		timeout += msg->timeout;
+
+	/*
+	 * Release the lock and wait, retake the lock afterwards.
+	 */
+	mutex_unlock(&adap->lock);
+	res = wait_for_completion_killable_timeout(&data->c,
+						   msecs_to_jiffies(timeout));
+	mutex_lock(&adap->lock);
+
+	if (data->completed) {
+		/* The transmit completed (possibly with an error) */
+		*msg = data->msg;
+		kfree(data);
+		return 0;
+	}
+	/*
+	 * The wait for completion timed out or was interrupted, so mark this
+	 * as non-blocking and disconnect from the filehandle since it is
+	 * still 'in flight'. When it finally completes it will just drop the
+	 * result silently.
+	 */
+	data->blocking = false;
+	if (data->fh)
+		list_del(&data->xfer_list);
+	data->fh = NULL;
+
+	if (res == 0) { /* timed out */
+		/* Check if the reply or the transmit failed */
+		if (msg->timeout && (msg->tx_status & CEC_TX_STATUS_OK))
+			msg->rx_status = CEC_RX_STATUS_TIMEOUT;
+		else
+			msg->tx_status = CEC_TX_STATUS_MAX_RETRIES;
+	}
+	return res > 0 ? 0 : res;
+}
+
+/* Helper function to be used by drivers and this framework. */
+int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
+		     bool block)
+{
+	int ret;
+
+	mutex_lock(&adap->lock);
+	ret = cec_transmit_msg_fh(adap, msg, NULL, block);
+	mutex_unlock(&adap->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cec_transmit_msg);
+
+/*
+ * I don't like forward references but without this the low-level
+ * cec_received_msg() function would come after a bunch of high-level
+ * CEC protocol handling functions. That was very confusing.
+ */
+static int cec_receive_notify(struct cec_adapter *adap, struct cec_msg *msg,
+			      bool is_reply);
+
+/* Called by the CEC adapter if a message is received */
+void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg)
+{
+	struct cec_data *data;
+	u8 msg_init = cec_msg_initiator(msg);
+	u8 msg_dest = cec_msg_destination(msg);
+	bool is_reply = false;
+	bool valid_la = true;
+
+	mutex_lock(&adap->lock);
+	msg->ts = ktime_get_ns();
+	msg->rx_status = CEC_RX_STATUS_OK;
+	msg->tx_status = 0;
+	msg->sequence = msg->reply = msg->timeout = 0;
+	msg->flags = 0;
+
+	dprintk(2, "cec_received_msg: %*ph\n", msg->len, msg->msg);
+
+	/* Check if this message was for us (directed or broadcast). */
+	if (!cec_msg_is_broadcast(msg))
+		valid_la = cec_has_log_addr(adap, msg_dest);
+
+	/* It's a valid message and not a poll or CDC message */
+	if (valid_la && msg->len > 1 && msg->msg[1] != CEC_MSG_CDC_MESSAGE) {
+		u8 cmd = msg->msg[1];
+		bool abort = cmd == CEC_MSG_FEATURE_ABORT;
+
+		/* The aborted command is in msg[2] */
+		if (abort)
+			cmd = msg->msg[2];
+
+		/*
+		 * Walk over all transmitted messages that are waiting for a
+		 * reply.
+		 */
+		list_for_each_entry(data, &adap->wait_queue, list) {
+			struct cec_msg *dst = &data->msg;
+			u8 dst_reply;
+
+			/* Does the command match? */
+			if ((abort && cmd != dst->msg[1]) ||
+			    (!abort && cmd != dst->reply))
+				continue;
+
+			/* Does the addressing match? */
+			if (msg_init != cec_msg_destination(dst) &&
+			    !cec_msg_is_broadcast(dst))
+				continue;
+
+			/* We got a reply */
+			msg->sequence = dst->sequence;
+			dst_reply = dst->reply;
+			*dst = *msg;
+			dst->reply = dst_reply;
+			if (abort) {
+				dst->reply = 0;
+				dst->rx_status |= CEC_RX_STATUS_FEATURE_ABORT;
+			}
+			/* Remove it from the wait_queue */
+			list_del_init(&data->list);
+
+			/* Cancel the pending timeout work */
+			if (!cancel_delayed_work(&data->work)) {
+				mutex_unlock(&adap->lock);
+				flush_scheduled_work();
+				mutex_lock(&adap->lock);
+			}
+			/*
+			 * Mark this as a reply, provided someone is still
+			 * waiting for the answer.
+			 */
+			if (data->fh)
+				is_reply = true;
+			cec_data_completed(data);
+			break;
+		}
+	}
+	mutex_unlock(&adap->lock);
+
+	/* Pass the message on to any monitoring filehandles */
+	cec_queue_msg_monitor(adap, msg, valid_la);
+
+	/* We're done if it is not for us or a poll message */
+	if (!valid_la || msg->len <= 1)
+		return;
+
+	/*
+	 * Process the message on the protocol level. If is_reply is true,
+	 * then cec_receive_notify() won't pass on the reply to the listener(s)
+	 * since that was already done by cec_data_completed() above.
+	 */
+	cec_receive_notify(adap, msg, is_reply);
+}